Carburetor attachment



Feb; 17, 1931. A, WRIGHT 1,792,884

CARBURETOR ATTACHMENT Filed May 5, 1926 2 Sheets-Sheet 1 ATTORNEYS Feb.17, 1 931.

A. WRIGHT CARBURETOR ATTACHMENT Filed May 5, 1926 2 Sheets-Sheet 2 4* 37T mo H67 ARTMZP /T Patented Feb. 17, 1931 PATENT OFFICE ART WRIGHT, OFAUSTIN, MINNESOTA CARBURETOR ATTACHMENT Application filed May 5,

a carburetor attachment having means mounted within the usual exhaustpassage of the engine and operable by the passage of exhaust gasestherethrough, to automaticallyeffect the opening of the choke valve uponinitial starting of the engine, and to maintain such valve in openposition during normal functionin of the engine.

A further ob] ect of the invention is to provide a carburetor attachmentcomprising a member pivotally mounted within the exhaust pipe of theengine, and having a connection with the carburetor choke valve whereby,when the engine is initially started, the exhaust gases being dischargedfrom the engine through the exhaust pipe, will impinge against thepivotally mounted member therein and cause it to be moved into openposition with the resultant opening of the choke valve to increase thesupply of air to the carburetor, and the member also tending to maintainthe choke valve in open position during normal functioning of theengine.

' A further object of the invention is to provide such an attachmenthaving a damper mounted in the usual exhaust passage of the engineadapted to obstruct the passage therethrough when the engine is at rest,and said member having a connection with the -carburetor choke valvewhereby, when the engine is initially started, the exhaust gasestherefrom will actuate said damper to cause 40 the choke valve to open,and a thermo-element connected with said damper and responsive to theheat of combustion to permit the damper to be gradually moved intofullopening position, thereby causing the choke valve to be similarlyopened, with the resultant automatic regulation of the supply of air tothe carburetor.

A further object is to provide a carburetor attachment having meansoperable by the ex haust of the engine to automatically open 1926.Serial No. 106,976.

the choke valve thereof, and tend to maintain it in open position duringnormal functioning of the engine, and means also being provided forpositively maintaining the choke valve in such open position upon ab- 5normal functioning of the engine as in the event of ignition failure,thereby preventing back pressure in the exhaust pipe of the engine fromcausing the choke valve to be moved into closing position with theresultant fiooding of the carburetor.

A further and more specific object isto provide a damper in the usualexhaust pipe of the engine which is operatively connected with the usualchoke valve of the carburetor for simultaneous operation therewith, andthe damper being secured to a shaft mounted in a heat-retaining memberor block secured to and encircling the exhaust pipe, and athermo-element connected with the shaft and functioning to normallymaintain the damper in closed position, whereby, when the engine isinitially started, the opening of the damper by the flow of exhaustgases through the exhaust pipe, will be retarded to gradually open thechoke valve to automatically increase the supply of air to thecarburetor as the engine heats up, after which the thermoelement willflex and will temporarily maintain the damper and choke valve in openposition after temporary interruption of the engine, and will cause thechoke valve to automatically be moved into closing position as theengine cools.

A further object is to provide a carburetor attachment of the above typeof simple and inexpensive construction, and which may readily be used inconnection with the carburetors of internal combustion engines ofordinary construction.

Other objects of the invention will appear from the followingdescription and the accompanying drawings and will be pointed out in theannexed claims.

In the drawings there has been disclosed a structure designed to carryout the various objects of the invention, but it is to be understood.that the invention is not confined to the exact features shown, asvarious 106 changes may be made within the scope of the claims whichfollow.

In the accompanying drawings forming part of this specification,

Figure 1 is a view in side elevation of a portion of an engine showingthe invention applied thereto;

F igure 2 is a plan view of the engine carburetor showing the meansprovided for positively maintaining the choke valve in open position,upon abnormal functioning of the engine;

Figure 3 is an enlarged detail sectional view on the line 3-3 of Figure1 showing the damper in normal closed position;

Figure 4 is a detailed sectional view on the line 44 of Figure 3;

Figure 5 is a perspective view of the thermo-element ad usting memberremoved from the heat-retaining block;

Figure 6 is a diagrammatic view illustrating the damper andthermo-element in normal inoperative osition, and the means provided foradjusta ly securing one end of the thermo-element to the heat retainingblock; and

Figure 7 is a view similar to Figure 6.

In the selected embodiment of the invention here shown, for purposes ofdisclosure, there is illustrated a portion of an internal combustionengine of ordinary construction, comprising the usual intake manifold11, carburetor 12, exhaust manifold 13 and exhaust pipe 14, having aconnection with the usual muiiler 15. The carburetor is provided withthe usual throttle valve 16 mounted upon the shaft 17 having an arm 18secured thereto which has a rod 19 connecting it with the usual meansprovided for operating the throttle. The usual choke valve 21 is alsoshown mounted upon the usual shaft 22 interposed in the air intake 23 ofthe carburetor, as particularly shown in Figure 2.

A feature of this invention resides in the novel means provided forautomatically opening the choke valve 21 of the carburetor after theengine has been initially started. This choke valve is adapted to benormally maintained in closed position as shown in Figure 1. An arm 24is terminally mounted upon the shaft 22 and has a rod 25 connecting itwith an arm 26 mounted upon a rock shaft 27 rotatably mounted in theupper portion of a split heat retaining member or block 28, the twohalves of which are securely clamped to the exhaust pipe 14 by means ofscrews or bolts 29. A damper 31 is secured to the rock shaft and isdisposed within the exhaust pipe 14 as shown in Figures 3 and 4. Thisdamper is normally held in closed position as shown, tending to obstructthe passage of the exhaust gases through the exhaust pipe when theengine is started. As soon as the engine is started, however, theexhaust gases will impinge against the damper 31 and cause it to bemoved into open position, as indicated by the dotted lines in Figure 7,Such opening of the damper 31 will cause the choke 21 to besimultaneously opened as a result of its connection therewith b means ofthe rod 25. A weight 32 is preferably mounted upon the shaft 27 and isadapted to return the damper 31 to its normal closed position, when theengine ceases to function, as shown in Figures 1, 3 and 4.- Other meansmay be employed, if desired, to return the damper 31 to its normalposition such, for instance, as a spring connected either to the arm 26,rod 25 or to the arm 24, it being essential that a means be provided forthus returning the damper to its normal closed position.

Thus it will be noted that when the engine crank shaft is being rotatedto initially start the engine, the choke valve 21 will remain in closedposition as shown in Figure 1, until the engine begins to fire, afterwhich the pres-' sure built up in the exhaust pipe 14 as a result ofsuch firing, will cause the damper 31 to be moved into open position,thereby automatically causing the choke valve to be 0 'ened to increasethe supply of air to the car uretor. The choke valve 21 will remain insuch open position as long as the engine continues to normally function,as a result of the flow of exhaust gases through the pipe 14 impingingagainst the damper 31, thereby holding it in open position. As soon asthe operation of the engine is interrupted, the weight 32 will tend tomove the damper 31, and

therefore, the choke valve 21, into closed or 1 normal startingpositions, as shown in Figure 1.

Means are provided, however, whereby the choke valve 21 may bepositively held in open position, should ignition temporarily failcausing the carburetor to become flooded, as a result of the choke valvebeing moved into closing position caused by the closing of the damper 31when the flow of gases through the exhaust pipe is interrupted. Suchmeans preferably consists of an extension 33 being provided upon the rod25, and having an upright portion 34 provided thereon adapted to bepositioned in the path of an arm 35, preferably integrally formed withthe throttle arm 18, as shown in Figure 2. When the throttle is in openengine-running position as shown in Figure 2, and the engine is normallyfunctioning, the upright portion 34 of the extension 33 will bepositioned as shown in Figure 2. Should ignition fail, however, causingthe choke valve to automatically be moved into closing position as shownin Figure 1, then the upright portion 34 of the extension 33 will bemoved into the path of the arm 35 as shown in dotted lines in Figure 2and full lines in Figure 1, in which position it may be engaged by thearm 35 and returned to open position, when the throttle arm 18 is movedinto throttle-closing position shown in dotted lines in Figure 2. Thusshould the carburetor accidentally become flooded as a result ofignition failure when attempting to start the engine, the throttle arm18 may be operated to close the throttle and thereby simultaneously toopen the choke valve 21, after which the engine may be turned over a fewtimes to draw the rich mixture out of the intake manifold and dischargeit into the exhaust pipe, after which the engine may be started. Thisextension 33 also functions to prevent back pressure in the exhaust pipe14: from closing the choke valve 21, should the supply of fuel to themotor suddenly he cut oil when the engine is running at a high speed. Insome instances it may be desirable to actuate the extension 33 by theusual spark control mechanism of the engine, instead of actuating it bythe throttle arm as herein described, the object being to provide meanswhereby the choke valve may be positively moved into and held in openposition.

Another important feature of this invention resides in the meansprovided for retarding the opening movement of the damper 31 when theengine is initially started. Such means preferably consists of athermo-element 35 coiled about one end of the shaft 27 and having oneend secured thereto. and its other end mounted in a slot 36 provided ina sleeve 37 adjustahly mounted in a bore 38 provided in the upperportion of the heat- .retaining block 28, as shown in Figure 3. One

end of the sleeve 27 is closed to provide a closure for the bore 38 whenthe adjusting member 37 is mounted therein as shown in Figure 4. Anannular outwardly extending flange 39 is also provided upon theadjusting member 37 adapted to be engaged by a suitable lock device suchas a washer 41, whereby it may be locked in adjusted positions by meansof a. screw 42 mounted in threaded engagement with the upper portion oftheblock 28. By relatively adjusting the position of the member 37within the bore 38, the thermoelement 35 may be put under more or lesstension to cause it to retard the opening of the damper 31 to properlyregulate the opening of the choke valve 21 as the engine starts. Thisthermo-element 35 may be so adjusted that when cold it will be exertinga slight force upon the damper 31 to retain it in closed position. Assoon as ignition takes place, however, the exhaust gases discharged fromthe engine through the exhaust pipe 14, will cause the latter to warm upwith the result that the element 35 will flex to permit the damper 31 togradually be moved into open position, thereby gradually opening thechoke valve to increase the supply of air to the carburetor as theengine warms up. When the exhaust pipe has become thoroughly heated, thethermo-element 35 will cause the damper 31 to be held in full-openposition, as shown by the dotted linesin Figure 4. Should the operationof the engine be temporarily interopen position as a result of thecoiled or flexed condition of the thermo-element 35. As the engine andexhaust pipe gradually cool, the damper 31 will be gradually moved intoclosing position, caused by the action of the thermo-element 35 as itcools.

A relatively wider slot or gap 43 is also provided in the adjustingmember 37, which, when used, will permit the damper 31 to immediatelyreturn to its normal closed position when the operation of the engine isinterrupted. Thus it will be noted that by the employment of theadjusting member 37 and the thermo-element 35 in connection with thedamper 31, the opening and closing of the choke valve 21 may becontrolled and regulated to meet the requirements of practically alltypes of internal combustion engines.

In the drawings, I have shown the damper .31 mounted in theheat-retaining block 28 and dependingtherefrom through an elongatedopening provided in the wall of the exhaust pipe 14, and into the pathof the exhaust gases flowing therethrough when the engine isfunctioning. It is to be understood that other means may be provided forsupporting the damper such, for instance, as a plug mounted in thewallof the exhaust pipe and having the damper shaft 27 axially mountedtherein and extending into the exhaust pipe; the main object being toprovide means within the exhaust pipe adapted to be actuated by gaseousflow therethrough to automatically effect the opening and closing of thecarburetor choke valve.

I claim as my invention:

1. The combination with an internal combustion engine including anexhaust pipe and a carburetor having a normally closed choke valve, of adamper mounted in said exhaust pipe and having a connection with saidchoke valve. said damper normally being held in closed position andadapted, upon initial starting of the engine, to be opened by the flowof gaseous fluid through said exhaust pipe, thereby causing said'chokevalve to be opened to increase the supply of air to saidcarburetor, and a thermo-element connected with said damper andfunctioning to retard the initial opening thereof and to temporarilymaintain said damper and choke valve in open positions, upon temporaryinterruption of said engine.

2. The combination with an internal combustion engine including anexhaust pipe and a normally closed carburetor choke valve, of a dampermounted in said exhaust pipe and normally obstructing the passagetherethrough, a shaft, a supporting member therefor secured to saidexhaust pipe, means connecting said damper with said choke valve, acoiled thermo-element mounted upon said shaft and having one end securedthereto, and the other end of said element having a connection With anadjusting member mounted for rotation in said shaft-supporting member,whereby the tension in said element may be adjusted to properly regulatethe damper opening when said engine is initially started and the exhaustgases therefrom impinge against said damper.

3. The combination with an internal combustion engine including anexhaust pipe and a carburetor having a choke valve adapted to benormally maintained in closed position when said engine is at rest, of aheatretaining member mounted upor and encircling said exhaust pipe, arock shaft mounted in said member and having a damper secured theretoand normally positioned to obstruct the passage through said exhaustpipe, means connecting said rock shaft with said choke valve wherebysaid valve will be opened when said damper is opened by the passage ofgaseous fluid through said exhaust pipe, and a thermo-element alsomounted upon and secured to said shaft and having one end secured tosaid heat-retaining member, said element being confined within saidmember whereby, when the engine is initially started, the heat of theexhaust gases passing through said exhaust pipe, will cause said elementto flex and permit the gaseous flow through said pipe to gradually andfully open said damper, thereby effecting a similar opening of saidchoke valve with the resultant automatic regulation of the supply of airto said carburetor.

4. The combination with an internal combustion engine having an exhaustpassage, a throttle, and a normally closed carburetor choke valve, of adevice mounted within said exhaust passage and having a connection withsaid choke valve whereby, when the engine is initially started, the flowof exhaust gases through said passage Will actuate said device and opensaid choke valve and tend to maintain it in open position during normalfunctioning of the engine, and means actuatable by movement of thethrottle to positively maintain said choke valve in open position.

5. The combination with an internal combustion engine having an exhaustpassage, a throttle, and a normally closed carburetor choke valve, of adevice mounted within said exhaust passage and having a connection withsaid choke valve whereby, when the engine is initially started, the flowof exhaust gases through said passage will actuate said device and opensaid choke valve and tend to maintain it in open position during normalfunctioning of the engine, and means connected with said choke valve andadapted to be actuated by movement of said engine throttle to positivelymaintain said choke valve in open position when the throttle is closed.

6. The combination with an internal combustion engine having an exhaustpipe and a carburetor, said carburetor having a normally closed chokevalve and a throttle arm, of a member pivotally mounted in said exhaustpipe and having a rod connecting it with said choke valve whereby, whensaid engine is initially started, the exhaust ases passing through saidexhaust pipe will actuate said member and open said choke valve and willtend to maintain said valve in open position during normal functioningof the engine, and means on said rod adapted to project into the path ofsaid throttle arm when said choke valve is in closed position, wherebysaid means may be engaged by said throttle arm to positively maintainsaid choke valve in open position when the throttle is closed.

in witness whereof, I have hereunto set my hand this 24th day of April,1926.

ART WRIGHT.

